A number of baling machines have been developed which compact loose materials, such as waste materials, into a relatively dense, compact bale. The compacted bales of waste material, often of a fairly uniform size, can then be more readily transported to a storage or disposal site at which they will occupy less space.
In particular, as the amount of available landfill space continues to diminish, the compaction of waste materials into dense, compact bales prior to their shipment and storage in a landfill becomes increasingly important in order to further reduce the space which the waste materials occupy within the landfill. In addition, with the increasing emphasis placed on environmental concerns and with the recent improvements in recycling technology which allow an even greater percentage of waste materials, such as paper, plastic and cans, to be recycled and reused, the baling of waste materials has become even more important since recyclable waste materials are generally compacted into a bale prior to their shipment to an appropriate recycling facility.
Conventional baling machines generally include a bin or hopper into which loose materials, such as waste material, are deposited. The deposited materials are generally collected in a charging passage defined within the baling machine. The charging passage is a longitudinally extending passage which typically has a parallelepiped shape, such as a rectangular solid shape.
Conventional baling machines also generally include a compacting ram assembly disposed within the charging passage and adapted for longitudinal movement therein. In particular, the compacting ram assembly generally includes a compacting ram platen which is adapted for reciprocating longitudinal movement through the charging passage between a retracted position and an extended position. In the retracted position, loose materials which are deposited in the hopper are collected in the charging passage. As the compacting ram platen is moved longitudinally forward from the retracted position to the extended position, the loose materials are urged through the charging passage and into a compaction chamber. The compaction chamber is also defined within the baling machine and is in communication with an exit end of the charging passage. Accordingly, the loose materials which are urged by the extending compacting ram platen through the charging passage are compacted into a bale within the compaction chamber.
The compaction chamber of such conventional baling machines generally has a rectangular solid shape having predetermined dimensions, including a predetermined width. In addition to the front face of the compacting ram platen in the extended position, the compaction chamber is typically defined by a floor, a ceiling and an end wall, opposite the compacting ram platen, which are fixed in position. The compaction chamber is further defined by a pair of opposed sidewalls which are adapted to cooperatively move so as to eject a compacted bale. In particular, once a bale has been formed in the compaction chamber, the bale is ejected such that the next bale can be compacted. The ejected bale can then be strapped or banded prior to shipment.
Conventional baling machines generally include a discharge ram assembly having a discharge ram platen for ejecting a compacted bale. Typically, the discharge ram assembly moves from a retracted position in which the discharge ram platen forms a first sidewall of the compaction chamber to an extended position by advancing the discharge ram platen through the compaction chamber such that the compacted bale is ejected therefrom. Generally, the discharge ram platen is longitudinally advanced in a direction perpendicular to the longitudinal axis of the charging passage.
Conventional baling machines typically operate in one of two modes, namely, a separation mode and a plug bale mode. In the separation mode, the second sidewall of the compaction chamber includes a door which is closed during the compaction operations and which opens once the compacted bale has been formed such that the compacted bale can be ejected from the compaction chamber. The door can then be closed prior to compacting the next bale.
In the plug bale mode, the second sidewall of the compaction chamber also includes a door. However, the door remains open during compaction operations in the plug bale mode and the rear portion of a previously compacted plug bale fills the opening in the sidewall of the compaction chamber during the compaction of the succeeding bale. Once the succeeding bale has been compacted, it can be ejected into the opening, thereby urging the previously compacted bale which had previously plugged the opening in the compaction chamber further downstream of the baling machine. The most recently compacted bale remains at least partially within the opening, however, to serve as the plug bale by filling the opening in the sidewall of the compaction chamber during the compaction of the succeeding bale.
The bales which are formed by conventional baling machines typically have a predetermined size as defined by the predetermined size of the compaction chamber. However, in some instances, oversized bales are formed. For example, the loose materials collected within the charging passage and urged by the compacting ram assembly into the compaction chamber can exceed the capacity of the compaction chamber, even following compaction, such that at least a portion of the compacted bale extends beyond the compaction chamber and into the charging passage.
In such instances, conventional baling machines are generally unable to eject the oversized bale from the compaction chamber since the door of conventional baling machines is adapted to open only to the predetermined width of the compaction chamber. Therefore, any attempts to eject the oversized bale from such conventional baling machines may damage the baling machine. Accordingly, upon formation of an oversized bale, the operator of the baling machine must generally temporarily suspend the baling operations and enter the compaction chamber to physically remove the excess material which extends beyond the compaction chamber such that the resulting bale fits within the compaction chamber and can be ejected. As will be apparent, this physical removal of the excess material is time-consuming, dangerous and laborious.
Accordingly, baling machines which are adapted to discharge oversized bales of compacted waste material have been developed. For example, U.S. Pat. No. 4,658,719 which issued Apr. 21, 1987 to Jerry L. Jackson, et al. and is assigned to Harris Press and Shear, Inc. discloses a mechanism for releasing oversized bales from a waste material baler. The waste baling machine of the Jackson '719 patent includes a discharge passage into which a compacted bale is ejected. The discharge passage has a predetermined width which defines the maximum width of a bale.
The discharge passage of the waste baling machine of the Jackson '719 patent includes a sidewall consisting of inner and outer sections. During the compaction and ejection of bales of the predetermined size, the inner and outer sidewall sections are positioned in a laterally adjacent relationship. However, upon the compaction of an oversized bale, the inner sidewall section can be lifted vertically and placed upon the outer sidewall section. Accordingly, the effective width of the discharge passage sidewall is decreased and, consequently, the width of the discharge passage is correspondingly increased. Thus, an oversized bale can then be ejected from the baling machine. However, the inner wall section of the waste baling machine of the Jackson '719 patent is generally relatively thick such that the vertical movement of the inner wall section requires a relatively large lifting force, typically supplied by a hydraulic motor. In addition, the inner and outer walls must be precisely machined such that the mating wall surfaces of the inner and outer wall sections can be slidably engaged.
Another waste material baling machine having a mechanism for discharging oversized bales is disclosed by U.S. Pat. No. 5,007,337 which issued Apr. 16, 1991 to Horace R. Newsom and is assigned to Mosely Machinery Company, Inc. The Newsom '337 patent discloses a horizontal waste baling machine which also includes a discharge passage, adjacent to and downstream of the compaction chamber and into which the compacted bales are ejected. In addition, the waste material baling machine of the Newsom '337 patent can include a discharge passage sidewall, adjacent the exit end of the charging passage. The exit end of the charging passage is generally defined as the end of the charging passage adjacent the compaction chamber.
The discharge passage sidewall defines the width of the discharge passage and, consequently, the maximum width of the compacted bale. In operation, the discharge passage sidewall has a normal position which defines the predetermined width of the standard compacted bales. In addition, the discharge passage sidewall is adapted to move a predetermined distance "d" laterally outward to a wider position in order to increase the width of the discharge passage such that an oversized bale can be discharged. Thus, the discharge passage sidewall of the waste material baling machine of the Newsom '337 patent has two positions, namely, a normal position and a wider position in which the discharge passage sidewall has been moved laterally outward by a predetermined distance "d"
As described above, some baling machines can operate in the plug bale mode, in which a previously compacted plug bale is disposed within an opening in the compaction chamber during the compaction of the succeeding bale. During the compaction process, however, the material in the compaction chamber is subjected to relatively large forces. Accordingly, the compaction chamber itself, including the previously compacted plug bale, must be adapted to withstand such large forces.
Typically, the plug bale is held within the opening in the sidewall of the compaction chamber by frictional forces between the bale and the discharge passage. In some instances, such as instances in which the plug bale has a relatively high moisture content or is slightly undersized, the frictional forces holding the plug bale within the opening defined in the compaction chamber can be overcome by the forces exerted on the material in the compaction chamber such that the plug bale is forced from the opening and advances in the discharge passage. Consequently, the bale being formed within the compaction chamber will typically be misshaped or missized due to the movement of the plug bale from the opening.
In order to further secure the plug bale within the opening defined in the sidewall of the compaction chamber, U.S. Pat. No. 5,081,922 which issued Jan. 21, 1992 to Brody W. Rudd, Jr., et al. and is assigned to C & M Company discloses a device for controlling the discharge of a bale from a solid waste baling machine. The waste baling machine of the Rudd '922 patent includes a discharge passage which is aligned with and in communication with the compaction chamber. Once the waste baling machine of the Rudd '922 patent has completed the compaction operations, the compacted bale is discharged through an opening in a sidewall of the compaction chamber and into the discharge passage. However, a rear portion of the compacted bale is retained within the opening in the sidewall of the compaction chamber as a plug bale during the compaction of the succeeding bale.
The longitudinally extending discharge passage of the waste baling machine of the Rudd '922 patent is defined by top and bottom plates and a fixed sidewall. The discharge passage is further defined by a laterally moveable sidewall which is mounted for lateral inward and outward incremental movement in a direction perpendicular to the longitudinal axis of the discharge passage. In particular, the laterally moveable sidewall is mounted for incremental movement inward and outward from a predetermined position in alignment with the exit end of the charging passage. Thus, the laterally moveable sidewall can be incrementally moved laterally inward following the ejection of a bale to press against and to increase the frictional forces on the ejected bale in the discharge passage during the compaction of the succeeding bale. Consequently, the ejected bale is maintained in position within the opening defined in the sidewall of the compaction chamber during the compaction of the succeeding bale.
Once a bale has been compacted by the waste baling machine of the Rudd '922 patent, it is ejected into the discharge passage. However, if there is excessive resistance to the ejection of the compacted bale, such as in instances in which the most recently compacted bale is larger than the previously compacted plug bale, the laterally moveable sidewall can also be incrementally retracted from the predetermined position in alignment with the exit end of the charging passage to reduce the resistance to the ejection of the compacted bale so as to thereby allow the compacted bale to be discharged into the discharge passage. Thereafter, the laterally moveable sidewall can again be incrementally moved laterally inward to more securely hold the plug bale in position during compaction of the succeeding bale.